1. Field of the Invention
The instant invention relates to a system and method to synchronize one or more shutters with a sequence of images.
More particularly, the instant invention relates to a system and method to synchronize one or more shutters on user-worn headgear with a sequence of images shown on a display by initially synchronizing the shutter(s) with the sequence of images using an initial synchronization signal generated externally to the headgear and by maintaining synchronization of the shutter(s) with the sequence of images using an ongoing synchronization signal generated independently by the headgear.
2. Description of the Related Art
Stereoscopic 3-D viewing systems for video games, computer graphics, movies, and the like are well known. In summary, they operate by showing a sequence of interlaced right-eye images and left-eye images on a display, by closing a right-eye shutter to block a viewer""s view of the display when a left-eye image is shown, and by closing a left-eye shutter to block the viewer""s view of the display when a right-eye image is show.
More particularly, as seen in the prior art system of FIG. 1, Control Unit 101 (which may be computer, a video game, or a movie projector) includes Image Generator 103, which provides a sequence of images to Display 105. The sequence of images is composed of a sequence of interlaced right-eye images and left-eye images. Synchronizing Circuit 107, which controls the timing of the images generated by Image Generator 103, also provides an Ongoing Synchronization Signal 109a to Infrared Transmitter 111 through Connection 112. The Ongoing Synchronization Signal 109a, which is transmitted in infrared form as Ongoing Synchronization Signal 109b to Infrared Detector 113 of 3-D Glasses 115, is used by Control Circuit 117 of 3-D Glasses 115 to synchronize the Right-eye Shutter 119a and the Left-eye shutter 119b of 3-D Glasses 115 with the right-eye and left-eye images shown on the display.
FIG. 2 shows another prior art system which is similar to the system shown in FIG. 1 but uses a hard-wired connection to carry the Ongoing Synchronization Signal to the 3-D Glasses. More particularly, it is seen in this FIG. 2 that Control Unit 201 (which may be computer, a video game, or a movie projector) includes Image Generator 203, which provides a sequence of images to Display 205. The sequence of images is composed of a sequence of interlaced right-eye images and left-eye images. Synchronizing Circuit 207, which controls the timing of the images generated by Image Generator 203, also provides an Ongoing Synchronization Signal 209 to 3-D Glasses 213 through hard-wired link 211. The Ongoing Synchronization Signal 209 is used by Control Circuit 215 of 3-D Glasses 213 to synchronize the Right-eye Shutter 217a and Left-eye Shutter 217b of 3-D Glasses 213 with the right-eye and left-eye images shown on the display.
Such prior art systems suffer a number of disadvantages. With regard to the system of FIG. 1, which employs the wireless delivery of the Ongoing Synchronization Signal, the use of a wireless transmitter such as an infrared transmitter increases the cost of the system. With regard to the system of FIG. 2, which employs the hard-wired delivery of the Ongoing Synchronization Signal, the wire connecting the 3-D Glasses to the Control Unit restricts movement and is clearly inconvenient to the viewer.
It is therefore an object of the present invention to provide a system and method to synchronize one or more shutters on user-worn headgear with a sequence of images shown on a display by initially synchronizing the shutter(s) with the sequence of images using an initial synchronization signal generated externally to the headgear and by maintaining synchronization of the shutter(s) with the sequence of images using an ongoing synchronization signal generated independently by the headgear. The initial synchronization signal generated externally to the headgear may be transmitted to the headgear through a hard-wired link which may be broken after the transmission of the initial synchronization signal. Alternatively, the initial synchronization signal generated externally to the headgear may be transmitted (preferably as visible light) to the headgear from the display upon which the sequence of images is shown.
Thus, the system and method of the instant invention eliminate the need for a continuous hard-wired connection to transmit an ongoing synchronization signal to the headgear. The system and method of the instant invention also eliminate the need to use a dedicated wireless transmitter to transmit an ongoing synchronization signal to the headgear.
Other objects and advantages will become apparent from the detailed description, claims, and accompanying drawings.